Load-handling pallet and method of assembly

ABSTRACT

A load-handling pallet ((10) comprises a plurality of separate plastics elements which are connected together to define an upper-load beating platform (20) with spaced support members (40) therebeneath between which the forks of a forklift truck can be located. The boards (20) forming the platform are mounted on transverse stringers (30) which are in turn secured to the top of blocks (40) by respective locator arrangements (32,41). Base boards (50) are secured to the bottom of the blocks (40) by further respective locator arrangements (52, 57, 152).

The present invention relates to a load-handling pallet for use withfork-lift trucks and to a method of assembly thereof.

Conventionally, load-handling pallets are made of wood. However, theseare unsuitable for use with foodstuffs as they are unhygienic. Toovercome this problem, pallets made from injection moulded plastics havebeen used but they have the disadvantage that they are expensive tomanufacture owing to the high tooling costs involved. One such pallet isdescribed in GB 1575143.

The present invention seeks to provide a pallet made from a hygienicmaterial which overcomes or substantially mitigates the aforementioneddisadvantages.

International Patent Application No. 91/13810 discloses a load handlingpallet comprising plastics elements defining an upper load-bearingplatform with cross-members and supporting blocks. The elements aresecured together by bolts with abutments which project beyond both majorsurfaces of the pallet. The disclosure of this document corresponds tothe preamble of claim 1. U.S. Pat. No. 5,197,396 also discloses a palletcomprising releasably-connected plastics elements.

According to the present invention there is provided a load-handlingpallet comprising a plurality of separate plastics elements defining atleast an upper load-bearing platform with at least two parallel crossmembers therebeneath and at least four blocks for location at thecorners of the platforms, which together with the cross members definespaces between which the forks of a fork-lift truck can be located,characterised in that said plastics elements are releasably connectedtogether by means of connection elements which, starting from the lowersurface of the pallet, extend through said blocks and into said crossmembers, or location elements integral therewith, but terminate beforethey reach the upper surface of the pallet.

An advantage of the above arrangement is that the pallet can bedismantled for cleaning and repair, and individual elements can beseparately replaced if damaged without the need for the whole pallet tobe discarded. Also the components may be transported in compact kit formbefore assembly, thus saving space and thus transport costs.

In one preferred embodiment of the invention the platform is constitutedby a plurality of parallel top boards which are supported on threestringers perpendicular thereto and nine support blocks, to the bottomof which are in turn attached five base boards. The top boards havebevelled sides which engage in corresponding dovetail grooves in thestringers. The stringers have plastics locator elements fixedly attachedthereto which engage with respective upper parts of the support blocks.The base boards also have plastics locator elements fixedly attachedthereto. Different types of locator element are provided depending ontheir positions on the base board. Six end locator elements are arrangedin two parts which are arranged on different base boards but which arearranged to interengage before being engaged with respective lower partsof the support blocks. Three one-piece locator elements, similar tothose on the stringers, are arranged centrally on three of the baseboards. The various interconnections may be supplemented by screw, boltor other connection elements.

Preferably, the plastics elements are made from polyvinyl chloride (PVC)or polypropylene (PP). This means that the pallet can be dismantled andwashed down and disinfected to comply with the rigorous regulationsgoverning the transportation and handling of foodstuffs. The elementsare extruded components which are cut to appropriate length to constructthe pallet. Some or all of the components, especially the supportblocks, may be injection-moulded.

In another embodiment of the invention the plurality of separateplastics elements are connected together predominantly by rustless steelself-locking type bolts or screws located within the central cellularcavities of the upper load-bearing platform boards fixed to purpose-madepre-drilled and threaded stainless steel or polypropylene (PP) elongatedlocating and fixing straps placed within the centre cavities of each ofthe upper load-bearing platform boards. The locating straps accommodatea plurality of separate bolts or screws. Alternatively each of the upperload bearing boards may have the central cavities extruded with a solidcentre core to accommodate self tapping rustless steel screws or bepre-tapped for rustless steel bolts. The two outer cells of all theupper load bearing platform boards including the supporting stringersmay be independently reinforced within themselves by the introduction ofpurpose made resin bonded "rot-proof" laminated "H section"purpose-designed timber inserts placed in the outer cavities;alternatively polypropylene (PP) inserts can be used and placed withinthe outer cavities of the cellular load bearing platform boards alongwith stringer support members therebeneath, under which the forks of afork lift truck can be located.

The outer corners of the blocks and upper platform boards may be fittedwith impact resistant rubber closure caps or alternatively polypropylenecellular board end closure caps may be used.

The blocks are hollow and made by an injection-moulded process. Theseare secured to the stringer support members by fixing through the sidesof the blocks into a plastic locating pad or insert pre-fixed to receivethe blocks.

These purpose-designed locating pads serve a dual purpose by allowingpositive anchorage of the whole pallet, They also prevent any distortionand keep the pallets true and square when in use. They also allow fastaccurate manufacturing of the pallets by use of multi-head roboticmachines, facilitating line production methods.

Preferably also, the elements comprise five additional blocks, fourlocated centrally of each of the sides of the pallet respectivelybetween the corner blocks, with the fifth one located at the centre ofthe pallet. A third cross-member, which is parallel to the other twocross-members and connected to the fifth block and two of the additionalfour blocks, supports the central region of the top boards. All blocksare fixed to the base boards by rustless fixings direct through andsecreted in the foot of the block which, when pallet assembly iscompleted, creates a bacteria free product allowing easy cleaning.

Preferably also plastic base boards are provided beneath the blocksfixed to the underside of the pallet.

A preferred embodiment of the present invention will now be described,by way of example only, with reference to the accompanying drawings ofwhich:

FIG. 1 is a partially exploded schematic view of a pallet according to afirst embodiment of the present invention;

FIG. 2 is an enlarged sectional view of the pallet of FIG. 1;

FIG. 3 is a further enlarged sectional view of the pallets FIGS. 1 and2;

FIG. 4 is a top plan view of the pallet of FIG. 1;

FIG. 5 is a cross-section of a pallet in accordance with a secondembodiment of the present invention through the top boards thereof;

FIG. 6 is a cross-section perpendicular to that of FIG. 5;

FIG. 7 is an enlarged, perspective and partly-sectioned view of theconnection between a top stringer element and a block of the pallet ofFIG. 5;

FIG. 8 is a further enlarged view of part of FIG. 7;

FIG. 9 is an underneath view of the base boards of the pallet of FIG. 5;

FIG. 10 is an enlarged, perspective and partly-sectioned view of theconnection between two base boards and a block of the pallet of FIG. 5;

FIG. 11 is an enlarged, exploded view of the end of a top board of thepallet;

FIG. 12 is a cross-section of a pallet in accordance with a thirdembodiment of the present invention;

FIG. 13 is a cross-section of the pallet of FIG. 12 but perpendicular tothe cross-section of FIG. 12;

FIG. 14 is an underneath view of the base boards of the pallet of FIG.12; and

FIG. 15 is a cross-section of a pallet in accordance with a fourthembodiment of the present invention.

Referring to the drawings, FIG. 1 shows a pallet 10 in accordance withthe first embodiment comprising a plurality of top boards 20 attached tothree top stringers 30. The top boards form a load-bearing platform. Thestringers are attached to nine blocks 40 to which are attached five baseboards 50.

The stringers have integral locator elements 32 which engage in the opentops of blocks 40. Locator elements 52, 57 integral with base boards 50engage in the open bottoms of blocks 40. The top and bottom locatorelements, and hence the top and bottom decks of the pallet 10, areinterconnected via connection elements, e.g. bolts 337.

Locator elements 52 will be described in further detail in connectionwith the embodiment of FIG. 9. However, it should be noted here thatlocator elements 52 are in two parts 53, 54 and that, for extrastrength, part 53 has fingers 153 which extend into the cavity of thenext base board 50 which is integral with the other part 54.

FIG. 3 shows how the top boards 20 have bevelled edges which slide intocorresponding dovetail grooves 31 in the top of the stringers 30. Eachboard is secured to the central stringer 30 by means of a rustlessscrew, pin or bolt connection element 37, FIG. 4 which is positionedfrom underneath during assembly. By disconnecting the respective element37, an individual top board 20 may be slid out of its grooves 31 forrepair, replacement or cleaning. Extra measures may be necessary forremoving the end ones of the boards 20.

FIGS. 5 to 11 show a pallet 510 in accordance with a second embodimentof the present invention.

The connection between a stringer 30 and a block 40 is shown in FIG. 7.At the location of the blocks 40, the stringers have welded, adhered orotherwise fixed thereto substantially rectangular locator members 32which slide into and are retained by correspondingly shaped recesses 41in the top of the blocks. The locator members 32 engage correspondingstop surfaces in the recesses to ensure precise positioning. Theinterconnection is protected against inadvertent disconnection by aratchet arrangement 42, an enlarged view of which is shown in FIG. 8.

The above arrangement means that for repair, replacement or cleaningpurposes, the entire top deck, comprising board 20 and stringers 30, canbe removed by simultaneously sliding all nine locator members 32 out oftheir corresponding recesses 41.

FIG. 9 shows an underneath plan view of the connection between the fivebase boards 50 and the nine blocks 40. As shown more clearly in theenlarged sectioned view of FIG. 10, the base boards also compriselocator members 52 fixed thereto. As shown in FIG. 9, these members 52are made up of two interengaging members 53, 54, three members 53 beingintegral with each of the two end boards 50 and two members 54 beingintegral with each of the three transverse boards 50. Afterinterconnection of the two base boards 50 by interengaging members 53,54, a block 40 is attached thereto by means of a clamping piece 45secured by a locking pin 46.

Three further locator members 57 are one-piece members similar tolocator members 32 and integral with the transverse boards 50 at acentral region thereof.

The top boards 20, stringers 30 and base boards 50 are all extrudedcomponents and are preferably provided with end caps such as 39, FIG. 11which after location are bonded into position to create hermeticallysealed components preventing the ingress of bacteria.

The blocks 40 are also hollow extruded components which are sealedaround the locators 32, 52, 57 with a clear silicone vulcanising agentsuch as RTV 595 which hermetically seals the joints but allows assemblyand dismantling of the pallet as required.

The above-described pallet has numerous advantages. It can be assembled,dismantled and repaired without the need for special tools, equipment orskilled labour. For repair purposes, only a limited number of differenttypes of component need to be kept in stock.

Pallets of a varying range of sizes can be made from one set ofextrusion dies; the extruded members are easily cut to the requiredlength.

Pallets can be shipped in kit form for manual or automatic assembly bythe user. The effective saving on space and transport costs is in theregion of

Various modifications can be made to the above described pallet. Forexample, the connections between the stringers 30 and the blocks 40 maybe supplemented by locking pins etc; if so, these pins need to beremoved before the top deck or platform can be removed as a single unit.

The central stringer 30 and/or the central base board 50 can be omittedif desired. In fact the base boards 50 can be omitted entirely. Ofcourse additional elements may be provided if desired for larger orstronger pallets.

FIGS. 12 to 14 show a modified pallet 110 in accordance with a thirdembodiment of the invention in which blocks 140 are connected bytransverse connection elements 137 to projections 136 integral withstringers 30. The bottom of blocks 140 are connected to the base boards50 by right-angled locator elements 152. In pallets 110 the top deck orplatform cannot be removed as a single unit, but the pallet is extremelyrobust, while still permitting the removal of individual elements, inparticular top boards 20.

In another modification, not shown, the locator elements are circular inplan view and are connected to individual stringers and/or base boards,for example, by respective rotating triple-leg engagement means.

In all examples, the base boards 50 and the upper deck comprising topboards 20 and stringers 30 are secured to each other by rustless pins,bolts, screws or other connection elements passing through the block 40.These connection elements (not shown in FIGS. 5 to 14) can be fixed topre-threaded stringer locator elements 32 to allow complete flexibilityfor removing individual components.

FIG. 15 shows a fourth embodiment of the present invention with such anarrangement of connection elements. Screw bolts 237 fasten together baseboards 250, stringers 230 and top boards 220 by means of a hollow orsolid block 240.

Each of the above described embodiments can be modified as appropriateto incorporate one or more features of any of the other embodiments.

It is claimed:
 1. A load-handling pallet comprising a plurality ofseparate plastics elements defining at least an upper load-bearingplatform with at least two parallel cross members therebeneath and atleast four blocks for location at the corners of the platforms, whichtogether with the cross members define spaces between which the forks ofa fork-lift truck can be located, said plastics elements beingreleasably connected together by means of connection elements which,starting from the lower surface of the pallet, extend through saidblocks and into said cross members, or location elements integraltherewith, but terminate before they reach the upper surface of thepallet and said cross members having integral locator elements whichslidingly engage with corresponding means at the top of the blocks.
 2. Apallet as claimed in claim 1, further comprising five additional blocks,four of which are located centrally of each of the sides of the palletrespectively between the corner blocks, and the fifth one of which islocated at the centre of the pallet, and a third cross member which isparallel to the other two cross members and connected to the fifthadditional block and two of the other four additional blocks to supportthe central regions of top boards forming the load bearing platform. 3.A pallet as claimed in claim 1, wherein base boards are provided beneaththe blocks around the lower edge of the pallet.
 4. A pallet as claimedin claim 3, wherein the base boards, have integral locator elementswhich are attached to the bottom of the blocks by means of attachingmeans.
 5. A pallet according to claim 4, wherein at least some of thelocator elements integral with the base boards comprise two parts eachintegral with a respective base board.
 6. A pallet as claimed in claim1, in which at least some of the plastics elements are secured togetherby separate connection elements.
 7. A pallet as claimed in claim 1, inwhich the connection elements extend from the lower surface of thepallet through the said blocks in respective bores, and in which thesaid bores do not penetrate the upper surface of the pallet.